Efficient genetic mapping strategies based on microsattelite marker polymorphism detection using the Polymerase Chain Reaction (PCR) assay have in recent years supplanted conventional mapping strategies such as restriction fragment length polymorphism (RFLP) analysis. Development of robotic assay stations such as the Applied Biosystems (ABI) PRISM 877 Integrated Thermal Cycler and automated electrophoresis and fluorescence based data collection systems such as the ABI PRISM 377 DNA Sequencer have further increased the power, speed and scope of genetic mapping. The Jackson Laboratory is well recognized for its scientific contributions in the field of mammalian genetics. Currently more than 87% of research projects at The Jackson Laboratory utilize marker based genetic mapping techniques. Throughput of current mapping projects at The Jackson Laboratory would be increased a minimum of six to nine fold with the availability of automated systems over manual non-fluorescence based PCR amplification and detection of microsattelite. Genotyping costs for each project would decrease due to lower reagent use of the fluorescent based instrument and technician time would be saved by automating the process of setting up PCR assays and manually entering typing data into analysis programs. Projects of 47% (15) of active staff members funded by 22 NIH grants would be greatly enhanced by the availability of this instrumentation. Additionally, the scope of future projects considered by investigators would be broadened, significantly improving the overall productivity of this institution's scientific staff. The scientific community would be served by enabling Jackson Laboratory staff to screen and make new models for human disease available more rapidly. Funds are requested to purchase the ABI PRISM 877 Integrated Thermal Cycler with associated computer hardware and 877 PCR operating software, 672A-90 Genescan operating software and Genotyper V2.0 Data Analysis software. This equipment would form the basis of an allele typing service which would reside in and be operated by the institution's DNA purification and sequencing as well as peptide and oligonucleotide synthesis services.